Analysis on detection of Hcy ,vWf and TF-PCA within 48 h of onset in patients with coronary heart disease / 国际检验医学杂志

Objective To observe the change of serum homocysteine (Hcy) ,plasma von willebrand factor (vWF) and whole blood tissue factor procoagulant activity (TF-PCA) within 48 h of onset in the patients with coronary heart disease (CHD).Meth-ods The relevant instrument was adopted to detect the level of serum Hcy ,plasma vWF and whole blood TF-PCA in 300 CHD pa-tients and 100 individuals undergoing the healthy physical examination ,and then the statistical analysis was performed.Three hundreds cases of CHD were divided into the stable angina group (SAP group ,n= 96) ,unstable angina group (UAP group ,n=100) and acute myocardial infarction group (AMI group ,n=104).Results The Hcy ,vWF and TF-PCA levels in the CHD patients were higher than those in the control group ,the difference was statistically significant (PUAP group> SAP group ,the difference was statistically significant (P<0.05).The vWF and TF-PCA levels in the AMI group and UAP group were higher than those in the SAP group with statistical difference (P<0.05).The Hcy level in SAP ,UAP and AMI patients complicated with diabetes and hypertension was significantly increased compared with the patients without complicating di-abetes and hypertension ,the difference was statistically significant (P<0.05).The vWF and TF-PCA levels had statistical differ-ence between the UAP group and AMI group(P<0.05).Conclusion Routinely detecting the levels of Hcy ,vWF and TF-PCA has an important clinical value for the diagnosis and curative effect observation in the patients with CHD.

Biochemical and biological evaluation of gyroxin isolated from Crotalus durissus terrificus venom

Gyroxin, a thrombin-like enzyme isolated from Crotalus durissus terrificus venom and capable of converting fibrinogen into fibrin, presents coagulant and neurotoxic activities. The aim of the present study was to evaluate such coagulant and toxic properties. Gyroxin was isolated using only two chromatographic steps - namely gel filtration (Sephadex G-75) and affinity (Benzamidine Sepharose 6B) - resulting in a sample of high purity, as evaluated by RP-HPLC C2/C18 and electrophoretic analysis that showed a molecular mass of 30 kDa. Gyroxin hydrolyzed specific chromogenic substrates, which caused it to be classified as a serine proteinase and thrombin-like enzyme. It was stable from pH 5.5 to 8.5 and inhibited by Mn²+, Cu²+, PMSF and benzamidine. Human plasma coagulation was more efficient at pH 6.0. An in vivo toxicity test showed that only behavioral alterations occurred, with no barrel rotation. Gyroxin was not able to block neuromuscular contraction in vitro, which suggests that its action, at the studied concentrations, has no effect on the peripheral nervous system.

Inhibition of local effects of Indian Daboia/Vipera russelli venom by the methanolic extract of grape (Vitis vinifera L.) seeds.

Although anti-venom therapy is available for the treatment of fatal bite by snakes, it offers less or no protection against the local effects such as dermo- and myonecrosis, edema, hemorrhage and inflammation at the bitten region. The viper species are known for their violent local effects and such effects have been commonly treated with plant extracts without any scientific validation in rural India. In this investigation, the methanolic extract of grapes (Vitis vinifera L.) seed was studied against the Indian Daboia/Vipera russelli venom-induced local effects. The extract abolished the proteolytic and hyaluronidase activities and also efficiently neutralized the hemorrhage, edema-inducing and myonecrotic properties of the venom. In addition, the extract also inhibited partially the pro-coagulant activity of the venom and abolished the degradation of Aα and Bβ chains of human fibrinogen. Thus, the extract possesses potent anti-snake venom property, especially against the local effects of viper bites.

Purification and partial characterization of a coagulant serine protease from the venom of the Iranian snake Agkistrodon halys

Agkistrodon halys is one of several dangerous snake species in Iran. Among the most important signs and symptoms in patients envenomated by this snake is disseminated intravascular coagulation. A thrombin-like enzyme, called AH143, was isolated from Agkistrodon halys venom by gel filtration on a Sephadex G-50 column, ion-exchange chromatography on a DEAE-Sepharose and high performance liquid chromatography (HPLC) on a C18 column. In the final stage of purification, 0.82 mg of purified enzyme was obtained from 182.5 mg of venom. The purified enzyme showed a single protein band by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), under reducing conditions, and its molecular mass was found to be about 30 kDa. AH143 revealed clotting activity in human plasma, which was not inhibited by EDTA or heparin. This enzyme still demonstrated coagulation activity when exposed to variations in temperature and pH ranging, respectively, from 30 to 40°C and from 7.0 to 8.0. It also displayed proteolytic activities on synthetic substrate. The purified enzyme did not show any effect on casein. We concluded that the venom of the Iranian snake Agkistrodon halys contains about 0.45 percent single procoagulant protein which appears to be a thrombin-like enzyme.(AU)